From e85a0adacf170634878fffcbf34b725aff3f49ed Mon Sep 17 00:00:00 2001 From: Boris Burkov Date: Fri, 1 Dec 2023 13:00:13 -0800 Subject: btrfs: ensure releasing squota reserve on head refs A reservation goes through a 3 step lifetime: - generated during delalloc - released/counted by ordered_extent allocation - freed by running delayed ref That third step depends on must_insert_reserved on the head ref, so the head ref with that field set owns the reservation. Once you prepare to run the head ref, must_insert_reserved is unset, which means that running the ref must free the reservation, whether or not it succeeds, or else the reservation is leaked. That results in either a risk of spurious ENOSPC if the fs stays writeable or a warning on unmount if it is readonly. The existing squota code was aware of these invariants, but missed a few cases. Improve it by adding a helper function to use in the cleanup paths and call it from the existing early returns in running delayed refs. This also simplifies btrfs_record_squota_delta and struct btrfs_quota_delta. This fixes (or at least improves the reliability of) generic/475 with "mkfs -O squota". On my machine, that test failed ~4/10 times without this patch and passed 100/100 times with it. Signed-off-by: Boris Burkov Signed-off-by: David Sterba --- fs/btrfs/qgroup.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs/btrfs/qgroup.h') diff --git a/fs/btrfs/qgroup.h b/fs/btrfs/qgroup.h index 15b485506104..be18c862e64e 100644 --- a/fs/btrfs/qgroup.h +++ b/fs/btrfs/qgroup.h @@ -274,8 +274,6 @@ struct btrfs_squota_delta { u64 root; /* The number of bytes in the extent being counted. */ u64 num_bytes; - /* The number of bytes reserved for this extent. */ - u64 rsv_bytes; /* The generation the extent was created in. */ u64 generation; /* Whether we are using or freeing the extent. */ @@ -422,6 +420,7 @@ int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *eb); void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans); bool btrfs_check_quota_leak(struct btrfs_fs_info *fs_info); +void btrfs_free_squota_rsv(struct btrfs_fs_info *fs_info, u64 root, u64 rsv_bytes); int btrfs_record_squota_delta(struct btrfs_fs_info *fs_info, struct btrfs_squota_delta *delta); -- cgit v1.2.3-70-g09d2